Published in 1980 with little promotion and a first printing of 5,000, “A People’s History” was, fittingly, a people’s best-seller, attracting a wide audience through word of mouth and reaching 1 million sales in 2003. Although Professor Zinn was writing for a general readership, his book was taught in high schools and colleges throughout the country, and numerous companion editions were published, including “Voices of a People’s History,” a volume for young people and a graphic novel.

Even liberal historians were uneasy with Professor Zinn, who taught for many years atBoston University. Arthur M. Schlesinger Jr. once said: “I know he regards me as a dangerous reactionary. And I don’t take him very seriously. He’s a polemicist, not a historian.”

In a 1998 interview with The Associated Press, Professor Zinn acknowledged that he was not trying to write an objective history, or a complete one. He called his book a response to traditional works, the first chapter, not the last, of a new kind of history.

“There’s no such thing as a whole story; every story is incomplete,” Professor Zinn said. “My idea was the orthodox viewpoint has already been done a thousand times.”

“A People’s History” had some famous admirers, including the actors Matt Damon andBen Affleck. The two grew up near Professor Zinn, were family friends and gave the book a plug in their Academy Award-winning screenplay for “Good Will Hunting.”

Oliver Stone was a fan, as was Bruce Springsteen, whose bleak “Nebraska” album was inspired in part by “A People’s History.” The book was the basis of a 2007 documentary, “Profit Motive and the Whispering Wind,” and even showed up on “The Sopranos,” in the hand of Tony’s son, A.J.

Professor Zinn himself was an impressive-looking man, tall and rugged with wavy hair. An experienced public speaker, he was modest and engaging in person, more interested in persuasion than in confrontation.

Born in New York in 1922, Professor Zinn was the son of Jewish immigrants who as a child lived in a rundown area in Brooklyn and responded strongly to the novels of Charles Dickens. At age 17, urged on by some young Communists in his neighborhood, he attended a political rally in Times Square.

“Suddenly, I heard the sirens sound, and I looked around and saw the policemen on horses galloping into the crowd and beating people,” he told The A.P. “I couldn’t believe that.”

“And then I was hit. I turned around and I was knocked unconscious. I woke up sometime later in a doorway, with Times Square quiet again, eerie, dreamlike, as if nothing had transpired. I was ferociously indignant.”

War continued his education. Eager to help wipe out the Nazis, he joined the Army Air Corps in 1943 and even persuaded the local draft board to let him mail his own induction notice. He flew missions throughout Europe, receiving an Air Medal, but he found himself questioning what it all meant. Back home, he gathered his medals and papers, put them in a folder and wrote on top: “Never again.”

He attended New York University and Columbia University, where he received a doctorate in history. In 1956, he was offered the chairmanship of the history and social sciences department at Spelman College, an all-black women’s school in segregated Atlanta.

During the civil rights movement, Professor Zinn encouraged his students to request books from the segregated public libraries and helped coordinate sit-ins at downtown cafeterias. He also published several articles, including a rare attack on the Kennedy administration, accusing it of being too slow to protect blacks.

He was loved by students — among them a young Alice Walker, who later wrote “The Color Purple” — but not by administrators. In 1963, Spelman fired him for “insubordination.” (Professor Zinn was a critic of the school’s non-participation in the civil rights movement.) His years at Boston University were marked by opposition to the Vietnam War and by feuds with the school’s president, John Silber.

Professor Zinn retired in 1988, spending his last day of class on the picket line with students in support of an on-campus nurses’ strike. Over the years, he continued to lecture at schools and to appear at rallies and on picket lines.

Besides “A People’s History,” he wrote several books, including “The Southern Mystique,” “LaGuardia in Congress” and the memoir “You Can’t Be Neutral on a Moving Train,” the title of a 2004 documentary about Professor Zinn that Mr. Damon narrated. He also wrote three plays.

His wife and longtime collaborator, Roslyn, died in 2008. They had two children, Myla and Jeff.

One of Professor Zinn’s last public writings was a brief essay, published last week in The Nation, about the first year of the Obama administration.

“I’ve been searching hard for a highlight,” he wrote, adding that he wasn’t disappointed because he never expected a lot from President Obama.

“I think people are dazzled by Obama’s rhetoric, and that people ought to begin to understand that Obama is going to be a mediocre president — which means, in our time, a dangerous president — unless there is some national movement to push him in a better direction.”